Route reliability record
ROC→ORD
Rochester to Chicago
- Flights
- 2,367
- Period
- September 2025 to August 2026
- Distance
- 528 mi
- Carriers
- 4
This route sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.3%. The late ones land an hour and a half behind schedule. That rests on 2,367 ROC to ORD flights, of which Republic Airways flew 676 at 81.9% on time.
Best time to fly ROC to ORD: a 8am–11am departure, ideally on a Saturday. Flights in that window arrived on time 88.7% of the time and Saturday flights 79.1%, against 75.0% for the route overall.
Republic Airways is the most reliable of the three carriers covered here at 81.9% on time across 676 flights.
Key figures
On time
75.0%
Arrivals under 15 minutes late, of 2,307 completed flights
Avg delay
95 min
Across delayed arrivals only, not all flights
Cancelled
2.41%
National rate is 1.89%
Best carrier
Republic
81.9% on time across 676 flights
These figures cover 2,367 flights between September 2025 and August 2026. Beyond the headline rate, 10.8% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Which airline is most reliable on ROC to ORD
The choice of carrier is not cosmetic here. Republic Airways arrives on time 81.9% of the time; United Airlines manages 66.9%. Sample sizes sit next to every figure, because a two-point gap across 587 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Republic Airways | 676 | 81.9% | 83 min | 2.37% | B |
| Envoy Air | 804 | 79.5% | 91 min | 2.24% | B |
| United Airlines | 587 | 66.9% | 90 min | 1.19% | C |
| SkyWest Airlinesthin sample | 300 | 63.0% | 123 min | 5.33% | D− |
The spread between Republic and United is 15 points, wide enough that it should decide the booking. On a hundred trips that is 15 more arrivals inside the on-time window.
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Best ways to make this trip
The most reliable ways to fly Rochester to Chicago
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 3 of the top 5 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. BUF → ORDBuffalo to Chicago | American Airlines | 80.0% | 82.2% | 2.72% | 11am–2pm, Wed | — |
| 2. ROC → ORDRochester to Chicago | Republic Airways | 80.0% | 81.9% | 2.37% | 8am–11am, Fri | — |
| 3. ROC → ORDRochester to Chicago | Envoy Air | 77.7% | 79.5% | 2.24% | 5am–8am, Sat | — |
| 4. BUF → ORDBuffalo to Chicago | Republic Airways | 75.6% | 78.0% | 3.04% | 8am–11am, Thu | — |
| 5. BUF → MDWBuffalo to Chicago | Southwest Airlines | 74.0% | 75.2% | 1.57% | 5am–8am, Wed | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 35 points, against 15 points between the best and worst carrier.
- 5am–8am705 flights84.0%
- 8am–11am205 flights88.7%
- 11am–2pm646 flights81.6%
- 2pm–5pm96 flights75.5%
- 5pm–8pm566 flights54.2%
- 8pm–5am149 flights60.0%
Scale runs 45% to 95%.
The 5pm–8pm window is where this operation falls apart: 54.2% on time, against 88.7% for the 8am–11am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5am–8am window is the busiest, with 705 flights scheduled in it.
Explore
Filter ROC to ORD by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On ROC to ORD, the best departure window is 8am–11am at 88.7% on time and the worst is 5pm–8pm at 54.2%, a wide gap of 34.5 points. All US flights leaving 8am–11am ran 83.9%.
- 5–8am84.0%
- 8–11am88.7%
- 11am–2pm81.6%
- 2–5pm75.5%
- 5–8pm54.2%
- 8pm–5am60.0%
best all US flightsScale 45% to 95%.
Across the year
When delays peak on this route
This route's year swings by 19 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
December is the weak month at 63.3% on time, against 82.2% in May. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. November was the busiest month here, with 225 flights.
Across the week, Saturday is the strongest day at 79.1% on time and Sunday the weakest at 69.6%, a spread of 10 points.
Delay causes
Why this route gets delayed
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 55,000 reported delay minutes.
- 36%Late-arriving aircraft
- 33%National Airspace System
- 28%Carrier
- 3%Extreme weather
- 0%Security
36% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 55,000 reported delay minutes here, that single category outweighs weather by 11 to one. The split is drawn from 54,654 reported delay minutes.
33% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 18,000 minutes out of 55,000, against a national NAS share of 21%.
Cancellations sit at 2.41% against a national 1.89%, which is ordinary. Diversions add another 0.13%.
Connections and stage length
What a delay here actually costs
10.8% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
The 528 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The return leg runs 73.3% on time across 2,348 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 2,367 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
Work out the risk of missing a connection in ORD after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. May runs 82.2% on time and December 63.3%, a swing of 19 points. If the dates move at all, move them out of December before you think about anything else. 2,307 completed flights over 12 months sit behind that.
Common questions
ROC to ORD questions
How often is ROC to ORD delayed?
About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 25.0% of the 2,367 flights in this analysis, against 22.7% nationally. Delayed flights are late by an hour and a half on average.
Which airline is most reliable on ROC to ORD?
Republic Airways leads at 81.9% on time across 676 flights. United Airlines is at the other end on 66.9%, a gap of 15 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on ROC to ORD?
The 8am–11am departure window is the strongest at 88.7% on time. The 5pm–8pm window is the weakest at 54.2%, 35 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are December delays on ROC to ORD?
December is the weakest month at 63.3% on time, compared with 82.2% in May. Across the year that is 19 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- ORD to ROC — the return legseparate record
- Chicago O'Hare International (ORD) delay statistics
- Republic Airways on ROC to ORD81.9%
- Envoy Air on ROC to ORD79.5%
- United Airlines on ROC to ORD66.9%
- SkyWest Airlines on ROC to ORD63.0%
- ROC to BWI, a related route82.3%
- LGA to ORD, a related route66.7%
- ROC to ATL, a related route79.6%
- Republic Airways on-time record81.9%
- Envoy Air on-time record79.5%
- United Airlines on-time record66.9%
- Why the first flight of the morning is statistically safest
- Same route, different airline: where the carrier you pick matters most
Direction matters. ROC to ORD and ORD to ROC are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.